It should be possible to compress the data stream between agents and principal

[jannfis]

In some environments, network traffic is more costly than CPU cycles. Thus, it should be possible to turn on optional compression of the data streams exchanged over the gRPC service between the principal and the agent.

Compression should be switchable on a per-agent basis, and be requested by the agent during connection setup. In a later point in time, we might want to have a switch to enforce compression on the principal's side.

[jgwest]

In discussing in standup, two ways this could be implemented:

• A) Compression at the message level

  • Every we time we send a message/event, we compress it, then include the compressed data as part of message/event
  • An example of a place where we would compress the data: https://github.com/argoproj-labs/argocd-agent/blob/main/internal/event/event.go#L139
  • If we send an Application .spec event, we might compress the .text of the .spec or .status
  • Theoretically possible, but B) is preferable

• B) Compression at the GRPC stream level

  • Easiest approach, presuming that Go GRPC library supports it (it seems to)
  • https://grpc.io/docs/guides/compression/
  • Transparent compression of the stream data by the GRPC library we are using

Our (strong) assumption of original requirements is that B is preferable, so we will investigate that.

[jannfis]

Yep, B) sounds perfectly reasonable to me.